The content encoder is composed of a 3-layer Conformer [1]} with a hidden size of 512.
The accent classifier is composed of a bidirectional LSTM with a hidden size of 256 for each direction, and 4 convolutional residual blocks with a hidden size of 256. Each convolutional residual block contains 2 convolution layers followed by LeakyReLU activation. The down-sampling rates of the residual blocks are 4, 2, 2 and 2, respectively. The \(\lambda \)  of GRL is \(5e^{-3}\) . The pre-trained ASR model for BNF extraction follows [1]}.
